English

Dissolving four-manifolds and positive scalar curvature

Geometric Topology 2007-05-23 v1 Differential Geometry Symplectic Geometry

Abstract

We prove that many simply connected symplectic four-manifolds dissolve after connected sum with only one copy of S2×S2S^{2}\times S^{2}. For any finite group G that acts freely on the three-sphere we construct closed smooth four-manifolds with fundamental group G which do not admit metrics of positive scalar curvature, but whose universal covers do admit such metrics.

Keywords

Cite

@article{arxiv.math/0306096,
  title  = {Dissolving four-manifolds and positive scalar curvature},
  author = {B. Hanke and D. Kotschick and J. Wehrheim},
  journal= {arXiv preprint arXiv:math/0306096},
  year   = {2007}
}

Comments

13 pages; to appear in Mathematische Zeitschrift

R2 v1 2026-07-22T16:55:12.467Z